A. L. S, B. J. A, A. D’Souza G, Nagaraj N. A clinical study of pulmonary function tests in patients with COPD exacerbation. Int J Adv Med [Internet]. 2017 Nov. 22 [cited 2025 Mar. 28];4(6):1645-8. Available from: https://www.ijmedicine.com/index.php/ijam/article/view/821